Method for restoring the operation of a yarn twist apparatus following a yarn break

ABSTRACT

A method for restoring the operation of a twist apparatus which imparts a prescribed twist to a yarn following a break in the yarn as it travels between a twist spindle of the twist apparatus and a wind-up package of the twist apparatus includes drawing off a twist yarn end from the wind-up package, securing it at a fixed securement point with a portion thereof having an intact twist turn, and cutting the drawn off twist yarn end. The twist yarn end from the wind-up package with the spin yarn end of the yarn from the twist spindle are then knotted or spliced to one another. Thereafter, the re-commencing of the operation of the wind-up package is effected with a delay relative to the re-commencing of the twist spindle operation such that the prescribed twist has propagated through the knotting or splicing location to the fixed securement point.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a method for restoring the operation of a yarn twist apparatus following a yarn break, the yarn twist apparatus being of the type comprising a twist spindle and a wind-up assembly and the operation restoring method including withdrawing the twisted yarn from the wind-up package, which winds up yarn from the twist spindle, and knotting or splicing the individual yarn ends of the twisted yarn with the spin yarn ends coming from the twist spindle, either mechanically or by hand, before the twist spindle and the wind-up package are again set in motion—that is, before they are again rotatably driven.

[0002] In connection with the afore-described operation restoring method, it is a requirement that, following the respective knotting or splicing together of the yarn ends, the twist yarn lengths which border on the knotted or spliced location of the yarn, are, to the extent possible, provided with the same twist turn as that of the entirety of the twist yarn length which has already been wound up on the wind-up package, in order to ensure that the full extent of the yarn wound up of the wind-up package has, uniformly throughout its length, the respective twist required for subsequent industry handling of the yarn.

[0003] Following the occurrence of a yarn break, it is relatively easy, with respect to the wind-up package, to unwind or draw off the twist yarn end, for preparation thereof for the knot or splice process, in a manner such that the drawn off yarn end is intact—that is, it has a predetermined or prescribed yarn twist, this being accomplished by drawing off from the wind-up package sufficient yarn in order to make available a yarn length having an intact twist turn, so that one can fix or secure the yarn piece extending from the wind-up package at a fixed securement location, and cutting through the drawn off yarn end at a location behind or upstream of the fixed securement point, as viewed with respect to the wind-up package, whereby a sufficient yarn length of the individual yarns is then available for knotting or splicing with the spin yarn ends extending from the twist spindle.

[0004] However, the yarn ends extending from the twist spindle which are available for the knotting or splicing process do not exhibit any twist turn so that only two individual spin yarn ends, which are not twisted together with one another, are available for the knotting or splicing process.

[0005] If one splices these non-twisted spin yarn ends with the yarn ends which have been drawn off from the wind-up package, without additional preparation, then, once the operation of the twist spindle and the wind-up package is restored, a considerable yarn length will be wound on to the wind-up package which lacks the predetermined twist turn.

[0006] In order to counter or oppose such an occurrence, it is typically undertaken to twist the spin yarn ends coming from the twist spindle either by hand in a conventionally denominated “hand twist” manual operation or to twist these yarn ends by an automatic twist means, as is disclosed, for example, in DE 32 43 410 C2; this latter approach, however, requires a considerable machine effort.

[0007] In order to connect the simple yarns—that is, the spin yarns, which are subsequently used as simple yarns or are twisted together with another yarn or other yarns into, for example, a twist yarn, it is known, from DE-PS 864, 075, to proceed in the following manner:

[0008] (a) in a first step, the two simple or, respectively, spin yarn, ends which are to be interconnected with one another are untwisted along a short stretch thereof, by, for example, displacing the twist into the adjoining yarn portion and then securedly maintaining the displaced twist thereat;

[0009] (b) in a second step, the two untwisted yarn ends are preferably pulled apart in opposing movements—that is, they are thinned—whereby the pulled apart extents of these yarn ends can be effected to approximately double the length of the untwisted portions of the yarn ends; and

[0010] (c) in a third step, the separated and pulled apart or, respectively, thinned, yarn ends are again twisted together by permitting the twist previously displaced into the adjoining yarn portion to return to the pulled apart yarn ends.

[0011] A method of the just-described type for connecting two spin yarn ends is not suitable as a method for restoring the operation of a twist apparatus after a yarn break situation in which the yarn ends coming from the twist spindle do not as yet comprise any twist turns, so that, consequently, for the knotting or splicing process, only two individual spin yarn ends which are not twisted together with one another are available.

[0012] In EP 0 570 477 B1, a method and an apparatus for connecting two twist yarn ends are described. This method and apparatus, however, are not oriented toward the restoration of the operation of a twist apparatus after a yarn break situation in which the yarn ends coming from the twist spindle are not twisted together with one another—that is, these twist spindle yarn ends do not as yet comprise any twist turns, as a consequence of which the knotting or splicing process must be undertaken with two individual spin yarn ends which are not twisted together with one another.

SUMMARY OF THE INVENTION

[0013] The present invention offers a solution to the challenge of providing, in contrast to the method disclosed in DE 32 43 410 C2, a simplified method for producing, after the occurrence of a yarn break, a restoration of the operation of the twist apparatus in a manner such that, in the region of the splicing or knotting location, the yarn present thereat has a substantially intact twist—that is, it has the prescribed twist.

[0014] In this manner, a build up of a sufficient length of yarn having the prescribed twist is achieved, after the restoration of the operation of the twist apparatus, in the region between the knotting or, respectively, the splicing, location, on the one hand, and the twist spindle or, respectively, the feed package disposed on the twist spindle, on the other hand, before the previously fixedly secured twist yarn end coming from the wind-up package is released from its secured position and, contemporaneously therewith, the winding operation of the windup package is resumed.

[0015] In this connection, it can be accepted that the twist turn of the yarn coming from the twist spindle may still extend, along a certain extent, into the respective portion of that yarn which lies upstream of the knotting or splicing location (as viewed relative to the travel direction of the yarn between the twist spindle and the wind up package, as the operation of the twist apparatus re-commences). The restored operation can be monitored to ensure that an equalization of the twist turns in the yarn ends which have been spliced or knotted together takes place.

[0016] The invention is described in the hereinafter following description of a preferred embodiment taken in connection with the sole FIGURE of the drawing.

BRIEF DESCRIPTION OF THE DRAWING

[0017] The sole FIGURE of the drawing shows, in partial sectional perspective view, one station of a doubling-twist machine which comprises, as its basic elements, a conventional doubling-twist yarn spindle A, as well as a wind-up assembly B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] The individual doubling-twist spindle and the wind-up assembly shown in the sole FIGURE of the drawing can each be, in particular, operated independent of the other respective doubling-twist spindles or wind-up assemblies of the entire doubling machine, and their operation can be, again, ceased independent of these other respective components.

[0019] The twist yarn, which is produced by operation of the doubling-twist yarn spindle A, travels during the wind-up process through an edge tail yarn guide 1, which is disposed on an extension of the spindle hollow axis; the twist yarn subsequently travels or passes through a conventional yarn delivery component 2, and, after passage through a yarn lead 3, is wound on a cross wound package S which is driven by, for example, a friction drive roller 5.

[0020] In the event of a yarn break, in order to restore the operation of the twist apparatus, a twist yarn end drawn from the wind-up package S is disposed in a respective splicer or, respectively, knotter, hereinafter generally designated as the splicer 6, and is secured therein at a fixed securement point such that, between this fixed securement point and the wind-up package S, there exists an intact twist turn along the extent of the drawn-off twist yarn end, while there also exists, behind or upstream of the fixed securement point (as viewed with respect to the travel direction of the yarn from the twist spindle A to the wind-up package S), two yarn ends of sufficient length available for the knotting or splicing process, these two yarn ends not being twisted together with one another.

[0021] Subsequently, the twist spindle is again set in motion until the twist turn which is prescribed for the completed wound up yarn has run back or propagated through the knotting or splicing location to the fixed securement point, before the wind-up process is again actuated by restoring the drive operation of the wind-up package S.

[0022] Instead of the splicer 6, which typically effects an automatic knotting or splicing of the yarn ends, the knotting together or splicing together of the yarn ends one with the other can also be accomplished by hand, whereby it must be ensured that the extent of the twist yarn end which has been drawn off of the wind-up package S has an intact twist turn until immediately before the actual knotting or, respectively, splicing, location.

[0023] The friction drive roller 5, which may be, for example, a single motor drive, is shown in the sole FIGURE of the drawing as a representative drive mechanism suitable for driving the rotation of the wind-up package S. It is important that the particular drive mechanism be controlled by, for example, a control device C, in a manner such that the recommencement of the operation of the wind-up package S is exactly controlled. The control device C controls as well the restored or continued operation of the drive mechanism 7 which drivingly rotates the twist spindle A. The time-delay restored operation of the wind-up package S can be controlled in a time manner by means of the control device C to commence after the control device has restored driving rotation of the twist spindle A by the drive mechanism 7.

[0024] A supporting software for supporting the operation of the control device C, which is not within the scope of the invention, can take into account, in particular, the spindle rotation per unit time, the twists per meter, and the starting time of the twist spindle.

[0025] As is schematically shown in the sole FIGURE of the drawing, the splicer 6 and, therewith, as well, the knotting or, respectively splicing location, are located between the yarn delivery device 2 and the edge tail yarn guide 1.

[0026] The specification incorporates by reference the disclosure of German priority document 101 24 270.0-26 of May 18, 2001.

[0027] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. 

What is claimed is:
 1. A method for restoring the operation of a twist apparatus which imparts a prescribed twist to a yarn following a break in the yarn as it travels between a twist spindle of the twist apparatus and a wind-up package of the twist apparatus, the method comprising: drawing off a twist yarn end from the wind-up package; securing the drawn off twist yarn end at a fixed securement point once the drawn off twist yarn end has been drawn off the wind-up package to an extent such that the drawn off twist yarn end comprises a portion with an intact twist turn; cutting the drawn off twist yarn end at a cutting location selected such that a sufficient extent of the twist yarn end is available below the fixed securement point for subsequently interconnecting this twist yarn extent with a spin yarn end of the yarn from the twist spindle; interconnecting the twist yarn end from the wind-up package with the spin yarn end of the yarn from the twist spindle by a selected one of knotting the yarn ends to one another and splicing the yarn ends to one another; re-commencing the operation of the twist spindle; and re-commencing the operation of the wind-up package in a time-delayed manner relative to the re-commencing of the operation of the twist spindle with the time delay being such that the prescribed twist which the completed twist yarn is to have has propagated through the location at which the yarn ends have been interconnected to one another to the fixed securement point.
 2. A method according to claim 1, and further comprising controlling the time-delayed re-commencement of the operation of the wind-up package, which occurs after the re-commencement of the operation of the twist spindle, via a control device.
 3. A method according to claim 1, wherein at least one of the spindle rotation per unit time, the twists per meter, and the high running time of the spindle is taken into account in setting the time-delayed re-commencement of the operation of the wind-up package. 